Abercrombie was the brother of architect and noted town planner Patrick Abercrombie. In 1909 he married Catherine Gwatkin (1881–1968) of Grange-over-Sands. They had 4 children, a daughter and three sons. Two of the sons achieved prominence, David Abercrombie as a phonetician and Michael Abercrombie as a cell biologist. Latter’s son Nicholas Abercrombie is a sociologist. A grandson, Jeffrey Cooper, produced an admirable bibliography of his grandfather, with brief but important notes, while a great-grandson is author Joe Abercrombie.

During World War I, he served as a munitions examiner, after which, he was appointed to the first lectureship in poetry at the University of Liverpool. In 1922 he was appointed Professor of English at the University of Leeds in preference to J. R. R. Tolkien, with whom he shared, as author of The Epic (1914), a professional interest in heroic poetry. In 1929 he moved on to the University of London, and in 1935 to the prestigious Goldsmiths’ Readership at Oxford University, where he was elected as a Fellow of Merton College. He wrote a series of works on the nature of poetry, including The Idea of Great Poetry (1925) and Romanticism (1926). He published several volumes of original verse, largely metaphysical poems in dramatic form, and a number of verse plays. Abercrombie also contributed to Georgian Poetry and several of his verse plays appeared in New Numbers (1914). His poems and plays were collected in ‘Poems’ (1930).

Lascelles Abercrombie suffered in his later years from serious diabetes, and died in London in 1938, aged 57.

A collection of literary and other manuscripts relating to Abercrombie is held by Special Collections in the Brotherton Library at the University of Leeds. The collection contains drafts of many of Abercrombie’s own publications and literary material; lecture notes, including those of his own lectures and some notes taken from the lectures of others, and a printed order of service for his Memorial Service in 1938.